aratok

new law that went into effect on 01-01-06 says that all vehicles from 99 onward must pass a emmisions test. I never thought I had a problem, but my 99 venture failed because of the evaporative emission control system malfunction. code number P0440. Does anyone know what the hell this is and how to repair? Thanks all

maxwedge

Start with a loose or not sealing gas cap after that it gets way more complex.

Glen_T

As maxwedge mentioned, a bad gas cap could easily cause it.

The code has to do with the evaporation system of the fuel vapors in the gas tank. The system is pressurized slightly to control the vapors and not allow them to release to the atmosphere. So, if you leave the cap off during a drive cycle or if it is loose, the system tries to pressurize the tank, it can't, and a code is set.

There is a fuel pressure on the top of the tank (part of the sending unit), and also a solenoid to control the tank pressure, as well as assorted other parts.

Did they say the code was active or inactive? If inactive, I'd be surprised they would fail you. If it is active, you should be able to check the code to make sure it is inactive after replacing the cap.

So, you might try a new cap, then check the code. If that isn't it, I'd look under the car for a loose or rotted fuel filler hose, vent hoses, etc.

Just some thoughts....Glen

GregA

Glen has it right.

If you want a little more information, I put up a description here.

Take Care,

__________________
Greg A.
2001 Chevy Venture w/some "enhancements" ~ 72K Miles (July 2007)
1992 Jeep Cherokee Laredo, 4.0L, Automatic ~ 131K Miles (July 2007)

Glen_T

Oops....re-read my post and Greg's, and realized that the system pulls a vacuum, not applies a pressureto the tank....however, the diagnosis is basically the same....sorry for the confusion....

markqc

In Ontario we have the "drive clean" program and I'm pretty sure they check to see if your gas cap is good before they will even test the vehicle. Do you know if your cap was tested? A loose cap will cause the check engine light to come on, but if your cap is good and you tighten it properly the light should go out after a few trips. Good luck.

Mark